While we are in "dream" mode I also have a plan for the perfect RIB.
11-12m with hard nose compartment containg compressor, oxygen cylinders and mixing panel. Twin inboard diesels with deep V hull and rear cockpit with 4 really good seats laid out 2 + 2. Full width dash with windscreen and full folding waterproof cover open at back but covered top and sides. small 3m dinghy hung off stern with put put motor. Small galley at one side, enough for soup and tea making. barbie mount at rear of cockpit over water.
Full clear deck space except for cylinder rack. Bench on front of cockpit full width. Canvas awning that would fit over main deck like tent so remote good weather diving can sleep on boat. A toilet would be good but not sure where it would go and not be in the road!
This would be the ideal boat for exploring the west coast and islands from Oban rather than trailing the little boat around and launching nearer in good weather